Don't just look at what he's writing about. Look at your own work. Push yourself to look for similarities in plot, character, meaning, etc. in the stories you've written. Are you able to find any? If so, are you surprised by what you found? What do you think it means when writers tend to write about similar things? What does this say about them as a writer or just as a person in general? When a writer doesn't deal with their obsessions in their work, does that still make them a good writer? Are we meant to write about our obsessions? Discuss, too, how different White's stories still are even when they share some aspects. Think about how perhaps these particular obsessions or similarities may be what is linking all of the stories together as a collection.
Note: Mention stories from the first half of the book, if they support this idea, but try to focus on the second half of the book. Besides this, feel free to choose which stories you mention. We are not forcing you to focus on any one in particular.